Two former ministers, Alan Milburn and Lewis Moonie, were fast-tracked by a government appointments watchdog to take up work with a Labour donating lobbying company which ignores a voluntary code of conduct not to pay or employ politicians.

Lord Moonie became an associate director and consultant for the lobbying company, Sovereign Strategy, last December, having stood down as defence minister in July 2003. He said yesterday: "My job will be to teach clients how to lobby government, not to lobby government for clients."

Mr Milburn took a paid post to run a seminar for Sovereign Strategy in March last year, having stood down as health secretary in June 2003.

The list of former ministers who have taken private sector jobs - due to appear in the annual report in two months' time - was released to the Guardian. It follows criticism of Baroness Symons, who stood down recently as international trade minister, for taking up a directorship with British Airways.

Sovereign Strategy was set up by Alan Donnelly, former Labour leader in the European parliament, and includes former cabinet minister Jack Cunningham and Baroness Billingham among its directors. It donated more than £55,000 to the Labour party between 2002 and 2004.

Its clients include Bernie Ecclestone, the Formula 1 boss, who had a £1m donation to Labour returned after a row over Labour's U-turn on cigarette sponsorship and advertising ban on racing cars. Other clients include the Premiership football league; Toyota, Japan; and Siemens Business Service.

The company is unusual in not belonging to the lobbyists' professional body, the Association of Professional Political Consultants, which has a code of conduct not to employ or pay any MP, peer or MEP.

The company confirmed this yesterday. "Sovereign is not a member of the APPC. As part of our corporate governance procedure we insist that all paid advice given by public figures is recorded in the appropriate register of interests and we are confident that this position has always been adhered to."

Details of the two former ministers' jobs have emerged in a list of outside jobs referred to the Advisory Committee on Business Appointments, the watchdog set up to monitor appointments offered to ministers and senior civil servants when they leave government service. No objections were raised.

The list also shows that former Scottish secretary Helen Liddell - due to be appointed a high commissioner to Australia - was allowed to become a consultant to the nuclear power operator, British Energy, provided she did not lobby ministers.

Lord Moonie also volunteered to the Guardian that he had since taken up two other directorships without restrictions imposed by the committee.

Civil servants faced much tougher restrictions. Sir Jeremy Greenstock, Britain's former special representative to Iraq, had to agree not to visit that country on business for six months last year after taking a job as special adviser to BP. Similar restrictions were put on Sir Stephen Gomersall, former ambassador to Japan, not to visit the country for six months when he became chief executive of the Japanese IT company Hitachi and on Sir Michael Pakenham, former ambassador to Poland, not to visit Poland for six months after taking two advisory posts and a non-executive directorship with French defence company Thales.

Sir Peter Gershon - the official responsible for proposing £21bn savings and 84,000 job cuts in Whitehall - has also been banned for a year from lobbying ministers after taking up private sector posts.

The most restrictive arrangement has been imposed on Tom Winsor, the former rail regulator, who has taken a job with a law firm that could be involved in advising clients of Network Rail or any clients with rail interests.

The agreement requires him to get the consent of Alistair Darling, the transport secretary, where any conflict of interest could arise. There is no appeal if he is stopped from taking up the job.

New jobs for old

Helen Liddell

From: Scottish secretary To: Consultant, British Energy Restrictions: No lobbying of ministers for two years